Ed you can fly a heli with the 4ch if it is a factory mode 1 4 ch. and you set channels 1-4 to "F" and the rest to "-" in your trainer menu in the 7c. See page 37 of your manual hope this helps

Thanks guys! I've been successfully flying other heli flyers on the slave as long as they wanted to do mode 2. I think you're right Thomas, I probably need the slave to be mode 1. The mode 1 flyer does have an older 72mhz 8channel futaba I'll see if my cord will match up. Thanks!